I had a service call last week to look at a outlet that had burned up. I am trying to surmise what happened to cause the small fire. Let me tell you what happened and you can tell me what really happened.

The outlet had a 6 outlet cover plugged into it*(without the hold down screw). The fire was actually between the outlet and the adaptor. No question where the fire happened. Big burn hole in the outlet and big burn hole in the adapter. This is obviously the weak spot in the system. The fire didn't happen until a delivery truck pulled down the service drop outside and then the outlet caught fire.

My question is how did the delivery truck cause the fire. Did it cause a low voltage-high current that the weak spot in the line could not handle?

BTW, they had more of the 6 outlet adapters plugged in over the outlet covers with no screws. More fires waiting to happen. They are fixed now.

what likely happen is a typical 15 amp receptacle is rated for only 15 amps for upto 3 hours of continious load. After 3 hours, that are rated only at 80% wich is 12 amps. With the number of plugs im a spliter, it is easy to put on 12-15 amp load on one. If the recept is on a 20 circuit, you can run up to 20 amps through a 12 (15)amp receptacle and not trip the breaker.

This is why cheap recepts melt after an extended time with a portable space heater. A 1500 watt heater draws 12.5 amps. a 12(15)amp will not carry it for long

At a place I worked at many years ago, which has many critical computers all over the place, the night cleaning crew used company vacuum cleaners which has twist-lock plugs on them. A few strategically placed outlets were twist-lock type. This was to prevent them from using outlets on circuits with computers. It could also prevent them from operating with plugs half-way pulled out due to pulling the cord as far as it would go.

I have a customer that has a mobile home with Aluminum wiring and when the flat screen and microwave and fish tank and dvd player are working it "trips" the circuit. When I come once a month he pays $150 for the service charge but won't pay to "fix it".

This sounds exactly like one of those situations we were all lead to believe would be prevented by using the CAFCIís, but as we now know, it most likely would not have helped. Iíll bet your inspector will still want one installed though, since the circuit has been altered by repair.